voteCommit for an aborted coordinator should send abort to the calling participant

The transaction coordinator removes itself from the coordinator catalog when it decides to abort, but it does so through a promise, which requires dropping the coordinator mutex. This allows a voteCommit to be processed by a coordinator in the kAborted state, which currently leads to no action. Instead, this should be treated the same as the non-existent coordinator case (see SERVER-37018), which sends abortTransaction to the participant that sent voteCommit.